JP2013231490A - Composite pipe, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance efficiency of work for exposing a connecting end part of a tube body.SOLUTION: A connecting end part of a tube body 12 can be exposed by tucking in the end part of the protecting layer 14 in an axial direction X of tube body 12 by a composite pipe 10 having a tube body 12 and a flexible protecting layer 14 which covers the outer peripheral surface of the tube body 12 and in which an unevenness is formed in the inner peripheral surface of the same. Consequently, it is possible to enhance efficiency of work for exposing the connecting end part of the tube body 12 for connecting to a tube joint for example.

Description

  The present invention relates to a composite pipe having a multilayer structure and a method for manufacturing the composite pipe.

  A composite pipe in which the outer peripheral surface of a tubular body is covered with a heat insulating material is often used for a hot water supply pipe or a water supply pipe that requires heat insulation. For example, Patent Document 1 discloses a composite pipe in which the outer peripheral surface of a pipe body is covered with a foam.

  In such a composite tube, since the foam is in close contact with the tube, it is difficult to lift up the end of the foam when exposing the connection end of the tube for connection to a pipe joint or the like. Also, when trying to expose the connecting end of the tube by cutting the end of the foam, it is necessary to work with great care not to cut or damage the tube, It takes time and effort.

Japanese Patent Laying-Open No. 2005-214228

  This invention considers the fact which concerns, and makes it a subject to improve the efficiency of the operation | work which exposes the connection end part of a tubular body.

  The invention described in claim 1 is a composite tube having a tube and a flexible protective layer that covers the outer peripheral surface of the tube and has irregularities formed on the inner peripheral surface.

  In the invention described in claim 1, by forming irregularities on the inner peripheral surface of the protective layer, the contact area inside the protective layer is reduced, and the frictional resistance between the outer peripheral surface of the tubular body and the protective layer is reduced. . As a result, the end of the tube can be exposed to the outside by tapping the end of the protective layer in the axial direction of the tube. Therefore, the efficiency of the operation | work which exposes the connection end part of a pipe body for connecting to a pipe joint etc. can be improved.

  According to a second aspect of the present invention, in the composite pipe according to the first aspect, the irregularities are formed in a bellows shape that repeats peaks and valleys in the tube axis direction.

  In the second aspect of the present invention, the contact area inside the protective layer can be reduced by the unevenness formed by the bellows shape, and the frictional resistance between the outer peripheral surface of the tubular body and the protective layer can be reduced. Moreover, the edge part of a protective layer can be made to touch easily by folding the edge part of a protective layer. Thereby, the efficiency of the operation | work which exposes the connection end part of a pipe body for connecting to a pipe joint etc. can be improved more.

  The invention according to claim 3 is the composite pipe according to claim 1 or 2, wherein the protective layer is a sheet-like member that covers the outer peripheral surface of the tubular body and that the end faces in the circumferential direction of the tubular body face each other. In addition to being formed, the outer peripheral surface is covered with a seamless holding layer.

  In the invention according to claim 3, by covering the outer peripheral surface of the protective layer with a seamless holding layer, the sheet-like member can be connected to the tube without joining the end faces in the circumferential direction of the tube-like member. Can be held around the body.

  According to a fourth aspect of the present invention, in the composite pipe according to any one of the first to third aspects, the protective layer is formed of a foamed resin.

  In invention of Claim 4, the heat insulation layer which consists of foamed resin can be formed in the circumference | surroundings of a pipe body by forming a protective layer with foamed resin. In addition, the weight of the composite pipe can be reduced.

  According to a fifth aspect of the present invention, in the composite pipe according to any one of the first to fourth aspects, a lubricating layer is formed between the tubular body and the protective layer.

  In the invention according to claim 5, since the frictional resistance between the outer peripheral surface of the tubular body and the protective layer can be reduced by the lubricating layer, the end portion of the protective layer can be easily pushed in the axial direction of the tubular body. Become. Thereby, the efficiency of the operation | work which exposes the connection end part of a pipe body for connecting to a pipe joint etc. can be improved more.

  In the invention according to claim 6, a flexible sheet-like member having a concavo-convex surface is wound around a tubular body with the concavo-convex surface inside, and the end surfaces of the sheet-shaped member in the circumferential direction of the tubular member are opposed to each other. And a step of forming a seamless holding layer on the outer peripheral surface of the sheet-like member by extrusion molding.

  In the invention according to claim 6, a composite pipe is manufactured in which the sheet-like member covers the outer peripheral surface of the tubular body so that the inner surface has an uneven surface, and the seamless holding layer covers the outer peripheral surface of the sheet-like member. Can do. Therefore, the uneven surface of the sheet-like member can reduce the frictional resistance between the outer peripheral surface of the tubular body and the sheet-like member, and the end of the sheet-like member is tapped in the axial direction of the tubular body. The end of the body can be exposed to the outside. Thereby, the efficiency of the operation | work which exposes the connection end part of a pipe body for connecting to a pipe joint etc. can be improved.

  According to a seventh aspect of the present invention, there is provided a step of forming a lubricating layer on the outer peripheral surface of the tubular body, and a flexible sheet-like member having a concavo-convex surface with the concavo-convex surface facing the inside through the lubricating layer. A step of winding around a tubular body and facing the end surfaces of the sheet-shaped member in the circumferential direction of the tubular body; and a step of forming a seamless holding layer on the outer circumferential surface of the sheet-shaped member by extrusion molding. It is a manufacturing method of the composite pipe | tube which has.

  In the invention described in claim 7, the same effect as that of claim 6 can be obtained. Moreover, since the friction layer can reduce the frictional resistance between the outer peripheral surface of the tubular body and the sheet-like member, the end portion of the sheet-like member can be easily pushed in the axial direction of the tubular body. Thereby, the efficiency of the operation | work which exposes the connection end part of a pipe body for connecting to a pipe joint etc. can be improved more.

  Since this invention set it as the said structure, the efficiency of the operation | work which exposes the connection end part of a tubular body can be improved.

It is a perspective view showing a compound pipe concerning an embodiment of the present invention. It is a cross-sectional view showing a composite pipe according to an embodiment of the present invention. It is a perspective view which shows the sheet-like member which concerns on embodiment of this invention. It is AA sectional drawing of Fig.2 (a). 1 is an overall view showing a composite pipe manufacturing apparatus according to an embodiment of the present invention. It is sectional drawing which shows the manufacturing apparatus of the composite pipe which concerns on embodiment of this invention. It is explanatory drawing which shows the manufacturing method of the composite pipe | tube which concerns on embodiment of this invention. It is a perspective view which shows the effect | action of the composite pipe which concerns on embodiment of this invention. It is a cross-sectional view which shows the effect of the composite pipe which concerns on embodiment of this invention. It is a sectional side view which shows the effect of the composite pipe which concerns on embodiment of this invention. It is a perspective view which shows the modification of the sheet-like member which concerns on embodiment of this invention. It is a perspective view which shows the modification of the sheet-like member which concerns on embodiment of this invention. It is a perspective view which shows the modification of the sheet-like member which concerns on embodiment of this invention. It is a perspective view which shows the modification of the sheet-like member which concerns on embodiment of this invention. It is explanatory drawing which shows the processing method of the sheet material which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. First, the composite pipe | tube which is embodiment of this invention is demonstrated.

  As shown in the perspective view of FIG. 1 and the cross-sectional view of FIG. 2 (a), the composite tube 10 has a tube body 12 formed of polybutene resin and a flexible body formed of flexible polyurethane foam. A sheet-like member 14 at the end, a seamless holding layer 16 formed of a thermoplastic elastomer, and a lubricating layer 18 formed on the outer peripheral surface of the tube body 12 are included.

  The sheet-like member 14 covers the outer peripheral surface of the lubricating layer 18 (covers the outer peripheral surface of the tubular body 12 via the lubricating layer 18), and the end surface of the tubular body 12 in the circumferential direction (hereinafter referred to as “circumferential direction S”). A protective layer is formed by facing and contacting each other (end surface 14A and end surface 14B), and the holding layer 16 covers the outer peripheral surface of the sheet-like member 14 seamlessly.

  As shown in the perspective view of FIG. 3 and FIG. 4A which is a cross-sectional view taken along the line AA of FIG. 2A, the sheet-like member 14 has a mountain valley in the axial direction of the tubular body 12 (hereinafter referred to as “axial direction”). X ”), and a plurality of bellows shapes are formed on the inner peripheral surface and the outer peripheral surface of the sheet-like member 14 (upper and lower surfaces of the sheet-like member 14 depicted in FIG. 3). Unevenness is formed, and the inner and outer peripheral surfaces of the sheet-like member 14 are uneven surfaces. 3 shows the sheet-like member 14 before being wound around the tubular body 12, and FIG. 4 (a) shows the sheet-like member 14 being wound around the tubular body 12. Yes.

  The sheet-like member 14 is formed by slicing a flexible polyurethane foam as a foamed resin foamed at an expansion ratio of 20 to 100 times into a sheet (plate) shape and cutting the sliced flexible polyurethane foam into a bellows shape. ing. Here, the expansion ratio means a value obtained by dividing the density of an unfoamed material by the density of the foamed material.

  The lubricating layer 18 is formed between the tubular body 12 and the sheet-like member 14. The lubricating layer 18 only needs to be configured to reduce frictional resistance between the outer peripheral surface of the tubular body 12 and the sheet-like member 14 without adversely affecting the tubular body 12 and the sheet-like member 14. You may be comprised with such a lubricant. For example, it can be composed of a silicon-based lubricant.

  Next, the manufacturing apparatus of the composite pipe | tube which is embodiment of this invention is demonstrated.

  As shown in the overall view of FIG. 5, the composite pipe manufacturing apparatus 20 includes a first storage roller (not shown), a second storage roller 22, a lubricant application device 24, an extruder 26, a die 28 as a mold, A cooling tank 30 and a tension device 32 are provided. In the following description, the direction from the second storage roller 22 toward the tension device 32 is referred to as a manufacturing direction Y. The first storage roller (not shown), the second storage roller 22, the die 28, the cooling tank 30, and the tension device 32 are arranged in this order with respect to the production direction Y, and the extruder 26 is located above the die 28. Has been placed.

  The tubular body 12 formed by extrusion molding and cured is wound in a roll shape on the first storage roller, and a sheet-like member 14 is wound on the second storage roller 22 in a roll shape. Yes. As shown in FIG. 2A, the sheet-like member 14 is formed in a strip shape so as to have a width that is substantially equal to the outer peripheral length of the tubular body 12 when the sheet-like member 14 is provided around the tubular body 12. Is formed.

  As shown in FIG. 5, the tubular body 12 is continuously drawn from the first storage roller and the sheet-like member 14 is continuously drawn from the second storage roller 22 by being pulled in the production direction Y by the pulling device 32. It is. As shown in the cross-sectional view of FIG. 6, the lubricant J is applied to the outer peripheral surface of the tube body 12 drawn continuously from the first storage roller by the lubricant application device 24. Thereby, the lubricating layer 18 is formed on the outer peripheral surface of the tubular body 12.

  As shown in the perspective views of FIGS. 5 and 7, the sheet-like member 14 is wound around the outer peripheral surface of the lubricating layer 18 near the supply port 36 of the die 28 into which the tubular body 12 and the sheet-like member 14 are fed. (Wrapped around the tubular body 12 through the lubricating layer 18). 7 shows the tubular body 12, lubrication in order to make it easy to understand how the sheet-like member 14 is wound and how the outer peripheral surface of the wound sheet-like member 14 is covered with the holding layer 16, which will be described later. Only the layer 18, the sheet-like member 14, and the holding layer 16 are depicted.

  As shown in FIG. 6, the extruder 26 extrudes the molten thermoplastic elastomer E to the die 28 with a screw 38. A through-hole 40 is formed in the die 28 as a passing portion through which the tubular body 12 around which the sheet-like member 14 is wound passes.

  The die 28 is cylindrical in the production direction Y in a state where the thermoplastic elastomer E extruded by the extruder 26 is melted when the tube body 12 around which the sheet-like member 14 is wound passes through the through hole 40. The holding layer 16 that covers the outer peripheral surface of the sheet member 14 is formed. That is, the holding layer 16 is extruded by the die 28.

  Extrusion molding of the holding layer 16 is performed such that the bellows-shaped valley portion 42 formed in the sheet-like member 14 is completely filled with the thermoplastic elastomer E, as shown in FIG. Further, the holding layer 16 is formed seamlessly in the circumferential direction S as shown in FIG.

  Further, as shown in FIG. 6, in the die 28, immediately before the outer peripheral surface of the sheet-like member 14 is covered by the holding layer 16, the upper surface of the lubricating layer 18, the sheet-like member 14, The air is sucked to the extent that the bellows shape of the sheet-like member 14 does not collapse (is not deformed) (arrow 44).

  As shown in FIG. 5, the cooling water W is stored in the cooling tank 30, and the holding layer 16 formed by the die 28 is cooled by the cooling water W when passing through the cooling tank 30.

  The tension device 32 includes a pair of rotating belts 46 and 48 that are arranged above and below the holding layer 16 cooled by the cooling bath 30 and sandwich the holding layer 16 therebetween. The rotating belts 46 and 48 are pressed against the outer peripheral surface of the holding layer 16 with a predetermined force. By rotating the rotating belts 46 and 48 in this state, the holding layer 16, the sheet-like member 14, and the tubular body 12 are integrally pulled in the manufacturing direction Y and moved at a speed of about 5 m / min.

  Next, the manufacturing method of the composite pipe | tube which is embodiment of this invention is demonstrated.

  Here, a composite pipe manufacturing method for manufacturing the composite pipe 10 using the composite pipe manufacturing apparatus 20 shown in FIG. 5 will be described. First, as shown in FIG. 5, the pipe body 12, the sheet-like member 14, and the holding layer 16 (composite pipe 34 described later) that have passed through the cooling layer 30 are simultaneously pulled in the manufacturing direction Y by the pulling device 32. The tubular body 12 and the sheet-like member 14 are continuously drawn out from the first storage roller and the second storage roller 22.

  Next, the lubricant layer 18 is formed on the outer peripheral surface of the tubular body 12 by applying the lubricant J on the outer peripheral surface of the tubular body 12 by the lubricant applying device 24 in the lubricant layer forming step.

  Next, in the sheet winding step, as shown in FIGS. 5 and 7, the lubricating layer 18 is formed in the vicinity of the supply port 36 of the die 28 so as to cover the lubricating layer 18 formed on the outer peripheral surface of the tubular body 12. The sheet-like member 14 is wound around the tubular body 12 via 18, and the end faces (the end face 14 </ b> A and the end face 14 </ b> B) of the sheet-like member 14 in the circumferential direction S are brought into contact with each other. Thereby, the sheet-like member 14 is wound around the tubular body 12 so as to have an uneven surface on the inside.

  Next, in the holding layer forming step, as shown in FIG. 6, the thermoplastic elastomer E extruded to the die 28 by the screw 38 of the extruder 26 is extruded in a cylindrical shape in the production direction Y in a melted state. A seamless holding layer 16 covering the outer peripheral surface of the member 14 is formed. Here, an intake step is performed before the outer peripheral surface of the sheet-like member 14 is covered by the holding layer 16. In the intake step, air between the upper surface of the lubricating layer 18 and the sheet-like member 14 is sucked out to the extent that the bellows shape of the sheet-like member 14 does not collapse (is not deformed) using an intake pump (not shown).

  Next, in the cooling step, as shown in FIG. 5, the holding layer 16 formed by the die 28 is cooled by the cooling bath 30 to form the composite pipe 34.

  Next, in the curing process, the composite pipe 34 is pulled out in the production direction Y by the tension device 32 and temporarily placed in a curing area (not shown), and the composite pipe 10 as the final finished product is obtained through the curing process in the curing area. It is formed.

  Next, operations and effects of the composite pipe, the composite pipe manufacturing apparatus, and the composite pipe manufacturing method of the embodiment of the present invention will be described.

  In the composite pipe 10 of the present embodiment, as shown in the perspective view of FIG. 8, the contact area inside the sheet-like member 14 (FIG. 8) is formed by forming irregularities on the inner peripheral surface of the sheet-like member 14 as a protective layer. Then, the upper surface of the lubricating layer 18 formed on the outer peripheral surface of the tubular body 12 and the contact area between the sheet-like member 14 and the friction resistance between the outer peripheral surface of the tubular body 12 and the sheet-like member 14 are reduced. Therefore, the end 52 (see FIG. 1) of the holding layer 16 is grasped by a human hand and slid toward the opposite side of the tube port of the tube body 12 with respect to the axial direction X (arrow 50). The end portion of the sheet-like member 14 can be tucked together with the end portion 52 of the holding layer 16. Thereby, the lubricating layer 18 formed on the outer peripheral surface of the end portion 54 of the tubular body 12 (joined end portion of the tubular body 12 joined to the pipe joint or the like) can be exposed to the outside. That is, the efficiency of the operation of exposing the connection end portion of the tube body 12 (in FIG. 8, the lubricating layer 18 formed on the outer peripheral surface of the end portion 54 of the tube body 12) for connection to a pipe joint is improved. be able to. For example, if the end of the composite tube 10 is in a state that does not move significantly, a person can tap the end of the sheet-like member 14 together with the end of the holding layer 16 with one hand.

  Further, since it is not necessary to cut the protective layer 16 covering the end portion 54 of the pipe body 12 in order to connect to the pipe joint, there is no fear that the pipe body 12 will be cut or damaged. Furthermore, the end of the sheet-like member 14 formed in a bellows shape is folded, so that the end of the sheet-like member 14 can be easily brought together.

  Further, as shown in FIG. 2A, in the composite tube 10 of the present embodiment, the outer peripheral surface of the sheet-like member 14 as a protective layer is covered with a seamless holding layer 16 to thereby surround the sheet-like member 14. Since the seam 56 of the portion where the end surfaces in the direction S (end surfaces 14A and 14B) face each other and are in contact with each other is covered with the holding layer 16, the end surfaces in the circumferential direction S of the sheet-like member 14 (end surfaces 14A and 14B). This sheet-like member 14 can be held around the tubular body 12 without joining the above.

  That is, in the composite pipe 10 according to the embodiment of the present invention, the sheet-like member 14 is held around the tubular body 12 even if the end portions in the circumferential direction S of the sheet-like member 14 are not joined to each other. 56 is not broken and the tube 12 is not exposed to the outside of the composite tube 10 or the sheet-like member 14 is not detached from the tube 12.

  Furthermore, since the holding layer 16 has no seam, the appearance is improved, and the tensile strength of the holding layer 16 itself can be increased.

  In addition, since it is not necessary to join the end portions of the sheet-like member 14 in the circumferential direction S, a welding operation for heating the joint portion of the sheet-like member 14 with a trowel or the like is not necessary. Troublesome work can be reduced.

  Furthermore, the sheet-like member 14 can be protected by the holding layer 16 that covers the outer peripheral surface of the sheet-like member 14.

  Moreover, in the composite pipe | tube 10 of this embodiment, the heat insulation layer which consists of foamed resin can be formed around the pipe body 12 by forming the sheet-like member 14 with foamed resin. That is, the composite pipe 10 can be used as a pipe having heat insulation properties. In particular, when the sheet-like member 14 is formed of a flexible polyurethane foam foamed at a high foaming ratio of 20 to 100 times, it can exhibit excellent heat insulation properties, and further has high flexibility. It can be demonstrated. That is, since the end portion of the sheet-like member 14 has sufficient softness, the end portion of the sheet-like member 14 can be reliably tucked in the axial direction X when the composite pipe 10 is connected to a pipe joint. it can.

  Furthermore, weight reduction of the composite pipe | tube 10 can be achieved by forming the sheet-like member 14 with a foamed resin.

  Further, in the composite pipe 10 of the present embodiment, the friction layer 18 can reduce the frictional resistance between the outer peripheral surface of the tubular body 12 and the sheet-like member 14, so that the sheet-like member 14 extends in the axial direction X. It becomes easier to knock the end.

  Cover the outer surface of the inner tube (polybutene tube with an outer diameter of 17 mm) by winding a jacket (soft polyurethane foam with a thickness of 3 mm) with the smooth surface without unevenness inside. In an experiment conducted using a two-layer composite pipe having an outer diameter of 19 mm, a resistance of 120 N was applied to push the end portion of the outer cover 25 mm in the axial direction of the inner pipe without applying a lubricant on the outer peripheral surface of the inner pipe. It was confirmed that a force of 67N was generated when a silicon-based lubricant was applied to the outer peripheral surface of the inner tube and the end portion of the outer jacket was pushed 25 mm in the axial direction of the inner tube. From this experimental result, it can be seen that by applying a lubricant on the outer peripheral surface of the inner tube, the resistance force generated when the end portion of the outer cover is squeezed in the axial direction of the inner tube can be halved.

  Further, in the composite pipe 10, the lubricating layer 18 makes it easy to insert the pipe body 12 into the pipe joint.

  Moreover, in the composite pipe 10 of this embodiment, since the holding layer 16 is formed by extrusion molding with the die 28, as shown in FIG. 10 which is a cross-sectional view of FIG. 9 and a BB cross-sectional view of FIG. Further, the outer peripheral surface of the holding layer 16 can be smoothed to improve the appearance, and the thickness of the holding layer 16 can be adjusted as necessary.

  9 and 10 illustrate an example of a state where the outer peripheral surface of the sheet-like member 14 is uneven. Thus, even when the outer peripheral surface of the sheet-like member 14 is uneven, the height difference of the unevenness is absorbed by the extruded holding layer 16 to smooth the outer peripheral surface of the holding layer 16. it can.

  Further, as shown in FIG. 6, before the outer peripheral surface of the sheet-like member 14 is covered by the holding layer 16, air is sucked from between the upper surface of the lubricating layer 18 and the sheet-like member 14, thereby FIG. As shown in FIG. 3, the lubricating layer 18 and the bellows-shaped top portion 58 formed on the sheet-like member 14 are brought into close contact with each other, or between the lubricating layer 18 and the bellows-shaped top portion 58 formed on the sheet-like member 14. The gap can be reduced. Thereby, since the outer peripheral surface of the sheet-like member 14 is covered with the holding layer 16 in a state where the outer peripheral surface of the sheet-like member 14 is smoothed, the outer peripheral surface of the holding layer 16 is made smoother and the appearance is improved. can do.

  The embodiment of the present invention has been described above.

  In the embodiment of the present invention, an example in which the tube body 12 is a polybutene tube has been described. However, the present invention is not limited to this, and the tube body 12 may be a tube formed of another material. For example, the tube body 12 may be a metal tube such as a stainless steel tube or a copper tube, or may be a resin tube such as a polybutene tube or a crosslinked polyethylene tube, or a tube having a resin tube lined on the inner peripheral surface of the metal tube. Also good. The tube body 12 is preferably a resin tube such as a polybutene tube or a cross-linked polyethylene tube because it is easy to perform processing such as cutting or take-up storage.

  In the embodiment of the present invention, a flexible polyurethane foam obtained by foaming the sheet-like member 14 at a foaming ratio of 20 to 100 times is sliced into a sheet (plate) shape, and the sliced flexible polyurethane foam is cut into a bellows shape. However, the sheet-like member 14 only needs to be formed of a foamed resin.

  Since the resin composition generally becomes softer as the expansion ratio becomes higher, the foamed resin forming the sheet-like member 14 preferably has a high expansion ratio and is foamed at an expansion ratio of 20 to 100 times. Is more preferable. The reason for this is that if the expansion ratio is smaller than 20 times, the flexibility of the sheet-like member 14 is impaired, the weight is increased, the cost is increased, and the expansion ratio is 100. When the ratio is larger than double, foam molding becomes difficult and the appearance is deteriorated.

  Furthermore, although the example which made the sheet-like member 14 the bellows shape was shown in embodiment of this invention, the unevenness | corrugation should just be formed in the inner peripheral surface. For example, the sheet-like members may be the sheet-like members 60, 62, 64, and 66 shown in the perspective views of FIGS. 11 to 14, the upper surfaces 60 </ b> A, 62 </ b> A, 64 </ b> A, 66 </ b> A of the sheet-like members 60, 62, 64, 66 are the inner circumferences when the sheet-like members 60, 62, 64, 66 are provided around the tube body 12. It becomes a surface.

  In the sheet-like member 60 shown in FIG. 11, the upper surface 60 </ b> A of the sheet-like member 60 has a wave shape that repeats peaks and valleys in the axial direction X, and the lower surface 60 </ b> B of the sheet-like member 60 is a flat surface. Depending on the shape of the sheet-like member 60, irregularities can be formed on the inner peripheral surface of the sheet-like member 60.

  The sheet-like member 62 shown in FIG. 12 is formed in a lattice shape by forming a plurality of prismatic through holes 68 having a rectangular cross section from the upper surface 62A to the lower surface 62B of the sheet-like member 62. Irregularities can be formed on the inner peripheral surface of the sheet-like member 60 also by such a shape of the sheet-like member 62. Note that a plurality of quadrangular prism-shaped concave portions may be formed on the upper surface 62A of the sheet-like member 62.

  The sheet-like member 64 shown in FIG. 13 is formed in a lattice shape by forming a plurality of prismatic through holes 70 having a rhombus cross section from the upper surface 64A to the lower surface 64B of the sheet-like member 64. Even with such a shape of the sheet-like member 64, irregularities can be formed on the inner peripheral surface of the sheet-like member 64. A plurality of prismatic concave portions having a rhombus cross section may be formed on the upper surface 64A of the sheet-like member 64.

  The sheet-like member 66 shown in FIG. 14 is formed by arranging a plurality of hemispherical protrusions 72 on the upper surface 66A of the sheet-like member 66, and the lower surface 60B of the sheet-like member 60 is a flat surface. Even with such a shape of the sheet-like member 66, irregularities can be formed on the inner peripheral surface of the sheet-like member 66. Further, the frictional resistance between the outer peripheral surface of the tubular body 12 and the sheet-like member 66 can be further reduced by the curved surface of the protrusion 72.

  The sheet-like member (for example, the sheet-like member 14, 60, 62, 64, 66) may be formed by any method. For example, it can be formed by slicing a flexible polyurethane foam into a sheet (plate) shape and subjecting the sliced flexible polyurethane foam to cutting or punching.

  FIGS. 15A and 15B show an example of manufacturing the sheet-like member 60 of FIG. 11 from a sliced flexible polyurethane foam (hereinafter referred to as “sheet material 74”). The sheet material 74 is fed in the feeding direction of the sheet material 74 (from right to left in FIGS. 15A and 15B) by the gear-like feeding rollers 76 and 78 that rotate while sandwiching the sheet material 74 up and down. The sheet material 74 is cut by the cutter 80 provided on the downstream side (left side) of the feeding rollers 76 and 78 with respect to the feeding direction of the sheet material 74.

  As shown in FIG. 15A, first, by rotating the feed rollers 76 and 78, the sheet material 74 is sandwiched and compressed between the peak portion 82 of the feed roller 76 and the valley portion 84 of the feed roller 78. The

  Next, by further rotating the feed rollers 76 and 78, the compression of the sheet material 74 is partially released, and the cutter 80 is placed at a position below the center in the thickness direction of the sheet material 74 in a state where the sheet material 74 has been partially released. A cut is made by.

  Next, as shown in FIG. 15 (b), by further rotating the feed rollers 76 and 78, the sheet material 74 is sandwiched between the valley portion 88 of the feed roller 76 and the peak portion 86 of the feed roller 78. Compressed.

  Next, by further rotating the feed rollers 76 and 78, the compression of the sheet material 74 is partially released, and the cutter 80 is disposed at a position above the center in the thickness direction of the sheet material 74 in a state where the sheet material 74 has been partially released. A cut is made by.

  After that, the sheet-like member 60 in which the corrugated shape is formed on one of the upper and lower surfaces is manufactured by repeating the operations shown in FIGS. 15 (a) and 15 (b). Instead of the cutter 80, a nichrome wire (heat wire) that generates heat by passing an electric current may be used.

  Moreover, in embodiment of this invention, the contact area inside the sheet-like member 14 is made small by forming an unevenness | corrugation in the inner peripheral surface of the sheet-like member 14 as a protective layer, and the outer peripheral surface of the tubular body 12 and a sheet | seat Although an example in which the frictional resistance with the tube-like member 14 is reduced is shown, the contact area inside the sheet-like member 14 with respect to the outer periphery area of the tube body 12 (in FIG. The ratio of the contact area between the upper surface of the layer 18 and the sheet-like member 14 is preferably 40% or more and 70% or less.

  Cover the outer surface of the inner tube (polybutene tube with an outer diameter of 17 mm) by winding a jacket (soft polyurethane foam with a thickness of 3 mm) with the smooth surface without unevenness inside. In an experiment conducted using a two-layer composite pipe having an outer diameter of 19 mm, a resistance force of 120 N was generated to push the end portion of the jacket 25 mm in the axial direction of the inner pipe, and the resistance force was 84 N or less. When the end portion of the outer cover can be easily crushed by 25 mm in the axial direction of the inner tube, and the ratio of the contact area between the inner tube and the outer cover to the outer peripheral area of the inner tube is smaller than 40%, It was confirmed that the outer cover was easily crushed when grasped with the hand.

  The resistance force that is generated when the end of the jacket is squeezed in the axial direction of the inner pipe is proportional to the ratio of the contact area between the inner pipe and the outer jacket to the outer peripheral area of the inner pipe. It can be seen that the ratio of the contact area between the inner tube and the outer cover to the outer peripheral area of the tube is preferably 40% or more and 70% (= (84N / 120N) × 100) or less. In the case where a lubricating layer is formed between the inner tube and the outer jacket, the friction resistance between the outer peripheral surface of the inner tube and the outer jacket becomes smaller. The ratio of the contact area with the jacket can be made 70% or more.

  Furthermore, in this embodiment, although the end surfaces (end surface 14A and end surface 14B) of the end-like sheet-like member 14 are made to oppose and contact, the example which covers the outer peripheral surface of tubular body 12 via lubrication layer 18 was shown, The sheet-like member 14 should just oppose end surfaces (end surface 14A and end surface 14B). That is, the end surfaces (end surface 14A and end surface 14B) of the sheet-like member 14 may be abutted with a gap. When making the heat insulation layer formed of the sheet-like member 14 exhibit high heat insulation properties, it is preferable that the end surfaces of the end-like sheet-like member 14 (end surface 14A and end surface 14B) are brought into contact with each other. Moreover, you may join the end surfaces (end surface 14A and end surface 14B) of the sheet-like member 14 with an adhesive agent, welding, etc. FIG. In this case, a joint seam is formed along the axial direction X in the protective layer. That is, the effect of the present invention is that “the sheet-like member 14 can be held around the tube body 12 without joining the ends of the sheet-like member 14 in the circumferential direction S”. It means that the joining of the end portions in the circumferential direction S of the sheet-like member 14 is not essential.

  Moreover, although the example which formed the sheet-like member 14 with the foamed resin was shown in this embodiment, it is not limited to this, You may form the sheet-like member 14 with another material which has flexibility.

  Furthermore, in this embodiment, although the lubrication layer formation process showed the example which forms the lubrication layer 18 on the outer peripheral surface of the pipe body 12 by apply | coating the lubricant J on the outer peripheral surface of the pipe body 12. If the end portion of the sheet-like member 14 can be brought close to the axial direction X, the lubricating layer 18 may not necessarily be formed between the outer peripheral surface of the tubular body 12 and the sheet-like member 14. That is, the sheet winding process, the holding layer forming process, the cooling process, and the curing process are performed, and the outer peripheral surface of the tubular body 12 is directly covered with the flexible sheet-like member 14 having the irregularities formed on the inner peripheral surface. A composite tube in which the outer peripheral surface of the sheet-like member 14 is covered with the seamless holding layer 16 may be manufactured.

  Even in such a composite tube, substantially the same effect as that of the composite tube 10 can be obtained. That is, by forming irregularities on the inner peripheral surface of the sheet-like member 14 as a protective layer, the contact area inside the sheet-like member 14 (contact area between the outer peripheral surface of the tubular body 12 and the sheet-like member 14) is reduced. Since the frictional resistance between the outer peripheral surface of the tubular body 12 and the sheet-like member 14 is reduced, the end 52 (see FIG. 1) of the holding layer 16 is gripped by a human hand, and the axial direction X By sliding the tube body 12 to the opposite side of the tube opening, the end portion of the sheet-like member 14 can be pushed together with the end portion of the holding layer 16. Thereby, the edge part 54 (joining edge part of the pipe body 12 joined to a pipe joint etc.) of the pipe body 12 can be exposed outside. Therefore, the efficiency of the operation | work which exposes the connection end part of the pipe body 12 for connecting to a pipe joint etc. can be improved.

  In the present embodiment, the holding layer 16 is made of the thermoplastic elastomer E. However, the holding layer 16 may be formed of a material that can hold the sheet-like member 14 around the tubular body 12. Since the cost is low and recycling is possible, the holding layer 16 is preferably formed of polyethylene, polypropylene, or a thermoplastic elastomer. The thickness of the holding layer 16 may be determined as appropriate. As described above, since the holding layer 16 is formed by extrusion molding in the die 28, the thickness of the holding layer 16 can be adjusted as necessary.

  Furthermore, the sheet-like member 14 shown in the present embodiment may be in close contact with the lubricating layer 18 formed on the outer peripheral surface of the tube body 12, and there is a gap between the lubricating layer 18. Also good.

  Moreover, the sheet-like member 14 and the holding layer 16 shown in the present embodiment may be in close contact with each other, or may have a gap therebetween. Further, the sheet-like member 14 and the holding layer 16 may be bonded. Even if there is a gap between the sheet-like member 14 and the holding layer 16, the holding layer 16 comes into contact with the sheet-like member 14 when pushing the holding layer 16 in the axial direction X. The ends of the two layers are tucked together with the ends of the holding layer 16.

  Furthermore, in this embodiment, although the example which comprised the protective layer by the one sheet-like member 14 was shown, you may comprise a protective layer by the several sheet-like member 14. FIG. For example, as shown in the cross-sectional views of FIGS. 2B and 2C, the protective layer may be constituted by two sheet-like members 14, or the protective layer may be constituted by three sheet-like members 14. Also good. In this case, the color, hardness, material, and the like may be different for each of the plurality of sheet-like members 14.

  In this embodiment, as shown in FIG. 4A, the bellows-shaped valley portion 42 formed in the sheet-like member 14 is completely filled with the thermoplastic elastomer E so that the holding layer 16 is Although the example which performs extrusion molding was shown, as shown in the side sectional views of FIGS. 4B to 4D, the holding layer 16 may be extruded.

  Furthermore, in this embodiment, although the example of the composite pipe 10 of the three-layer structure comprised by the pipe body 12, the protective layer (sheet-like member 14), and the holding | maintenance layer 16 was shown, this embodiment shows the pipe body 12. And it can apply to the composite pipe of 2 or more layers which has a protective layer (sheet-like member 14).

  In the present embodiment, the tubular body 12 that has been extruded and cured is wound around the first storage roller. However, the tubular body 12 is extruded by a die as a mold and then cooled in a cooling tank. The composite pipe 10 may be manufactured from the pipe body 12 immediately after being formed.

  Furthermore, although the example which cools the retention layer 16 with the cooling tank 30 by water cooling (cooling water W) was shown in this embodiment, you may cool the retention layer 16 with other cooling methods, such as air cooling.

  Further, in the embodiment of the present invention, the example in which the pair of rotating belts 46 and 48 are arranged vertically and the composite pipe 34 (holding layer 16) is sandwiched is shown. The composite pipe 34 (holding layer 16) may be sandwiched between the two. Alternatively, the tensioning device 32 may be configured by only one rotating belt, and the rotating belt may be pressed against the holding layer 16. Further, the composite pipe 34 (holding layer 16) may be sandwiched between three or more rotating belts.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect.

10 Composite tube 12 Tubing 14, 60, 62, 64, 66 Sheet-like member (protective layer)
14A, 14B End face 16 Retaining layer 18 Lubricating layer S Circumferential direction (tubular circumferential direction)
X axis direction (tube axis direction)

Claims (7)

Tube,
A flexible protective layer covering the outer peripheral surface of the tubular body and having irregularities formed on the inner peripheral surface;
Having a composite tube.   The composite pipe according to claim 1, wherein the irregularities are formed in a bellows shape that repeats a mountain valley in the tube axis direction.   2. The protective layer is formed of a sheet-like member that covers an outer peripheral surface of the tubular body and has end surfaces in the circumferential direction of the tubular body facing each other, and the outer peripheral surface is covered with a seamless holding layer. Or the composite pipe | tube of 2.   The composite pipe according to claim 1, wherein the protective layer is formed of a foamed resin.   The composite pipe according to any one of claims 1 to 4, wherein a lubricating layer is formed between the pipe body and the protective layer. A step of winding a flexible sheet-like member having an uneven surface around a tubular body with the uneven surface inside, and opposing end surfaces of the sheet-like member in the circumferential direction of the tubular body;
Forming a seamless holding layer on the outer peripheral surface of the sheet-like member by extrusion molding; and
The manufacturing method of the composite pipe | tube which has. Forming a lubricating layer on the outer peripheral surface of the tubular body;
Winding a flexible sheet-like member having a concavo-convex surface around the tubular body with the concavo-convex surface inside through the lubricating layer, and opposing the end faces of the sheet-shaped member in the circumferential direction of the tubular body; ,
Forming a seamless holding layer on the outer peripheral surface of the sheet-like member by extrusion molding; and
The manufacturing method of the composite pipe | tube which has.